上海交通大学物理与天文系激光等离子体教育部重点实验室, 上海 200240
强激光脉冲与气体靶作用是产生高功率太赫兹(THz)辐射的一个重要途径。利用光电离电流模型研究了同向传播的波长为0.8 mm 的激光及其半频光为1.6 mm 的激光与气体作用产生强太赫兹辐射的过程。讨论了气体种类、激光振幅、双色激光相位差对离化电流的影响。与通常的0.8 mm 激光及其倍频光组合相比，在同等激光强度下利用半频光组合可以产生更强的太赫兹辐射，约为倍频情况下的两倍。通过改变双色激光偏振方向的夹角，当两个光的偏振垂直时，即使半频光的强度远低于基频光，离化电流的方向也由半频光的偏振方向决定。
光谱学 太赫兹辐射 双色激光 离化电流模型 偏振夹角 激光与光电子学进展
2015, 52(7): 073001
1 中国科学院 长春光学精密机械与物理研究所 应用光学国家重点实验室, 长春 130033
2 中国科学院大学, 北京 100039
3 国工程物理研究院 激光聚变研究中心, 四川 绵阳 621900
4 上海交通大学 物理系, 激光等离子体教育部重点实验室, 上海 200240
从分子运动的角度，通过对不同分子沉降过程的量化计算，发现不同污染物沉降速率的差异，由此提出了一种包含污染物化学成分的有效洁净度的概念。有效洁净度从描述物质沉降过程的输运方程出发，通过计算不同理化性质的污染物分子沉降速率对不同污染物进行区分，并将该信息与原标准下的洁净度信息结合。使用美国国家标准与技术学会(NIST)数据库提供的数据代入有效洁净度理论，计算了几种主要污染物的有效洁净度数值，计算结果与法国LIL激光装置中有代表性的污染物的沉降速率及曝光后形成污染的程度进行了对比，与实验观测基本吻合。
大激光工程 激光损伤阈值 有效洁净度 污染物化学成分 large laser engineering laser-induced damage threshold effective cleanliness chemical component of contaminations 强激光与粒子束
2014, 26(11): 111010
上海交通大学激光与等离子体教育部重点实验室, 上海 200240
介绍了激光诱导击穿光谱(LIBS)技术的原理，重点讨论了该技术在液体样品方面的技术发展和应用，分析并比较了选取不同样品形式(液体内部、液体表面、液体喷流、液滴以及将液体转化为固体等)的优劣，指出提高元素检测限的关键。液体LIBS 技术因其可在线、快速检测等优点，在环境检测、污水处理、生物医药、工业控制等诸多方面具有巨大的应用潜力。
光谱学 激光诱导击穿光谱 液体 元素检测 激光与光电子学进展
2014, 51(10): 100001
Author Affiliations
Abstract
Key Laboratory for Laser Plasmas (Ministry of Education) and the Department of Physics, Shanghai Jiao Tong University, Shanghai 200240, China
We briefly review the development of gain-switched rare-earth-doped fiber lasers and their applications in wavelength conversion to mid-IR, supercontinuum generation, and medicine in recent years. We illustrate the similarities between gain-switching and Q-switching techniques that will provide tools for the design and optimization of the gain-switched fiber lasers. From the nature of the gain-switched fiber lasers, benefits of this kind of lasers to 2-μm region and in-band-pumped (two-level system) laser systems are obvious. Advantages of in-band-pumped 2-μm lasers are discussed and analyzed with a simple numerical simulation in terms of Tm-doped fiber lasers. We also propose the key factors in the development of the gain-switched fiber lasers and predict the future tendency.
Fiber optics infrared Laser theory Lasers fiber Lasers pulsed Photonics Research
2013, 1(1): 01000052
上海交通大学激光等离子体教育部重点实验室, 上海 200240
对相位调制合束技术产生高重复频率短脉冲技术进行了研究，利用两个电光开关的错位削波技术对连续种子激光进行斩波、分束，并分别用相同的相位调制器调制，通过相干合束产生窄带脉冲。对多种相位调制信号调制光脉冲的过程进行了数值仿真，研究了不同相位调制函数调制引起的光脉冲特性变化规律，通过实验验证了本方法产生高重复频率短脉冲的科学性。利用2.5 GHz带宽的实验仪器压缩出了脉宽为60 ps、重复频率为1 GHz的高重复频率短脉冲。
激光器 高重复频率短脉冲 相位调制合束 错位削波 强度调制
Author Affiliations
Abstract
We propose a new phase-modulation-combination system for the generation of arbitrarily shaped repetition rate pulses. In this system, the pulses from two electro-optic switches are modulated and interferentially combined, thereby improving the shaping resolution and narrowing the pulse width. This method allows the arbitrary tuning of pulse width, repetition rate, and temporal profile in an all-fiber configuration. The system is compatible with and can be easily embedded in other systems to achieve higher pulse energy and higher pulse repetition rate.
060.5060 Phase modulation 060.2280 Fiber design and fabrication 140.3538 Lasers, pulsed Chinese Optics Letters
2013, 11(3): 030603
Author Affiliations
Abstract
1 Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai 201800, China
2 Department of Physics, Shanghai Jiaotong University, Shanghai 200240, China
Diode-end-pumped continuous-wave (CW) Tm:YAP and Tm:YLF slab lasers are demonstrated. The a-cut Tm:YAP and Tm:YLF slabs with doping concentrations of 4 at.-% and 3.5 at.-%, respectively, are pumped by fast-axis collimated laser diodes at room temperature. The maximum CW output powers of 72 and 50.2 W are obtained from Tm:YAP and Tm:YLF, respectively, while the pump power is 220 W, corresponding to the slope e±ciencies of 37.9% and 26.6%, respectively.
板条激光器 激光二极管端面抽运 Tm:YAP Tm:YLF 140.3580 Lasers, solid-state 140.3480 Lasers, diode-pumped 140.3380 Laser materials Chinese Optics Letters
2011, 9(9): 091406
Author Affiliations
Abstract
1 Shanghai Institute of Fine Mechanics and Optics, Chinese Academy of Science, Shanghai 201800, China
2 Department of Physics, Shanghai Jiao Tong University, Shanghai 200240, China
Multi-pass mini-slab (MPMS) Nd:YAG ceramic lasers with a single-mode output of 38 W is examined corresponding to an optical conversion efficiency of 47%. Although several characteristics of various ceramic samples are almost similar, such as transmission, emission and absorption spectra, cross section, and thermal conductivity, their optical conversion efficiencies can vary from 5% to 40%. We present a simple technique to on-line measure the influence of scattering loss of ceramic on laser performance. This particular technique provides convenience and accuracy in pre-monitoring ceramic sample quality. Experimental results of the MPMS Nd:YAG ceramic laser agree with evaluations.
多程 微型板条激光器 陶瓷激光器 效率 140.3480 Lasers, diode-pumped 140.3530 Lasers, neodymium 140.3580 Lasers, solid-state 290.5820 Scattering measurements Chinese Optics Letters
2011, 9(2): 021402
1 中国科学院上海光学精密机械研究所强激光材料重点实验室， 上海 201800
2 中国科学院研究生院， 北京 100049
3 上海交通大学物理系， 上海 200240
选择中频电磁感应加热提拉法生长出了透明、基本无散射和气泡、无包裹物的高质量的铥(Tm)取代钇（Y）的原子数分数为2%的Tm:YLiF4（YLF），并采用X射线衍射（XRD）法对晶体进行了物相分析。测试TmYLF晶体的吸收光谱并计算了Tm离子对不同波长的吸收系数和吸收截面。同时测定其荧光光谱并分析了3H4－3F4和3F4－3H6跃迁产生的发射峰。对TmYLF晶体进行了激光实验，当输入功率为160 W时，获得了54.4 W的激光输出，斜率效率为35.6%，最大光光转换效率为31.2％。
材料 2 μm激光晶体 提拉法 激光输出
